Wang Shangen (played by Andy On) of the International Security Bureau led Wan Fei (played by Jay Chou) and other subordinates to Jordan to escort Kenner, a scientist who created a variant of the smallpox virus. Unexpectedly, Wang Shangen rebelled and kidnapped Kenner. Wan Fei was seriously injured in the head, and his sweetheart in the same team also died in this mission. Three months later, the virus developed by Wang Shangen and others caused the death of all the people on a cargo ship, and he was ready to sell vaccines for huge profits; Wan Fei was told in the hospital that the bullet in his head could not be removed, and his nerve damage caused him to be in danger of death in two weeks. Wan's mother revealed to him that he had a brother who had been separated for many years. In order to fulfill his mother's wish, Wan Fei went to Kuala Lumpur to find his brother Wan Yang (played by Nicholas Tse). Dr. Jian, who was traveling with Wan Fei on the plane, happened to be a virus expert that Wang Shangen and his gang were going to use to replace Kenner. Dr. Jian was hijacked by Wan Yang sent by Wang Shangen, and Wan Fei rescued him. Because they belonged to different camps, the brothers had to fight each other...